Many systems include a drive train with a prime mover for producing power and a transmission for altering the form of the power produced by the prime mover and transmitting the power to other components of the system. For example, vehicles may include a prime mover, such as an internal combustion engine, for producing power and a transmission, such as a step-change mechanical transmission, for receiving power from the prime mover and transmitting the power to other components of the vehicle at a speed different from which the prime-mover produces the power. Adding a motor/generator to such a drive train may allow for operating the drive train with increased efficiency. However, many existing drive trains do not include a motor/generator and are not well adapted for the addition of a motor/generator.
At least one motor/generator has been disclosed with provisions for adding the motor/generator to at least one configuration of an existing drive train. For example, U.S. Pat. No. 6,133,659 (“the '659 patent”) shows a motor/generator mounted between an engine and a transmission. The motor/generator of the '659 patent includes a housing that is attached at one end to the engine and at the other end to the transmission. The motor/generator further includes a rotor and a stator. One end of the rotor of the motor/generator is bolted directly to the crankshaft of the engine. A coupling in the form of a plate connects to the other end of the rotor of the motor/generator. The coupling also attaches to a planar surface of an input shaft of the transmission, thereby attaching the rotor of the motor/generator to the input shaft of the transmission.
Although the motor/generator of the '659 patent is adapted for connection between the engine and transmission of some existing drive trains, the design includes disadvantages. Because the rotor is bolted directly to the crankshaft of the engine, the motor/generator may impose undesirable loads on the bearings that support the crankshaft. Additionally, bolting the rotor of the motor/generator directly to the crankshaft of the engine limits flexibility in operating the drive train, as the crankshaft of the engine and the rotor of the motor/generator cannot be rotated independent from one another. Furthermore, the design only provides for connecting the rotor of the motor/generator to a planar mounting surface of a transmission input shaft, and many transmission input shafts do not include such planar mounting surfaces.
The motor/generator of the present disclosure solve one or more of the problems set forth above.